Apparatus for individual therapy planning and positionally accurate modification of an optical element

ABSTRACT

A method for detecting structures within an optical element of an eye and processing the optical element as a function of the detected structures includes acquiring, by a detection device, geometric data of an eye, transferring, by the detection device, the geometric data of the eye to a controller, calculating, by the controller, target coordinates for a processing device including a laser, the processing device being connected to the controller, and applying a beam produced by the laser to the eye according to the target coordinates calculated by the controller so as to process the optical element.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/257,934, which is a continuation of U.S. Pat. No. 9,463,115, filed onFeb. 9, 2009, which is a U.S. National Phase application under 35 U.S.C.§ 371 of International Application No. PCT/EP2007/006898, filed on Aug.3, 2007, which claims priority to German Patent Application No. DE 102006 036 800.2, filed on Aug. 7, 2006.

FIELD

The present invention relates to an apparatus for individual therapyplanning and positionally accurate modification of an optical element.Specifically, the present invention relates to a navigation apparatusfor optically analyzing and modifying an optical element and, moreparticularly, to a navigation apparatus for optically analyzing andmodifying an aged human eye to treat presbyopia.

BACKGROUND

In ophthalmology, it is known to shape the cornea by surgery on tissueto thereby correct myopia, hyperopia and astigmatisms. This is doneusing laser beams, for example, of an ArF excimer laser, whose radiationpulses have a wavelength of 193 nm. In addition to laser-surgical,refractive correction of the cornea, methods have been described for thetherapy of the eye lens to treat presbyopia. These methods attempt, byway of suitable cuts or bubble fields, to return the hardened lens to acondition in which it can be better deformed by the capsular bag orciliary muscle. This is basically intended to partially restore theaccommodative ability of the lens.

Document WO2005/070358 describes simple cutting geometries, which areintended to increase the flexibility in homogeneous materials. Thedisclosed methods and cutting geometries do not take into account theindividual geometry or the inner structure of the eye lens.

SUMMARY

In an embodiment, the present invention provides a method for detectingstructures within an optical element of an eye and processing theoptical element as a function of the detected structures. The methodincludes acquiring, by a detection device, geometric data of an eye,transferring, by the detection device, the geometric data of the eye toa controller, calculating, by the controller, target coordinates for aprocessing device including a laser, the processing device beingconnected to the controller, and applying a beam produced by the laserto the eye according to the target coordinates calculated by thecontroller so as to process the optical element.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in even greater detail belowbased on the exemplary figures. The invention is not limited to theexemplary embodiments. All features described and/or illustrated hereincan be used alone or combined in different combinations in embodimentsof the invention. The features and advantages of various embodiments ofthe present invention will become apparent by reading the followingdetailed description with reference to the attached drawings whichillustrate the following:

FIG. 1 is a schematic view of a navigation apparatus according to anembodiment of the present invention;

FIG. 2 is a schematic view of the construction of the human eye lens;

FIGS. 3a and 3b are schematic views illustrating two cutting patterns inthe optical element; and

FIG. 4 is a schematic view of a further embodiment of the presentinvention, which is used in partial phacoemulsification.

DETAILED DESCRIPTION

An embodiment of the present invention is to provide an inventivenavigation apparatus for optically analyzing the inner structure and/orthe individual position of an optical element and for modifying and/orprocessing the optical element, said navigation apparatus including adetection device having an aperture smaller than 0.25, and furtherincluding a processing device adapted to be guided along, or in a fixedrelationship to, the analyzed inner structure of the optical element.

An embodiment of the present invention provides an ophthalmo-surgicaldevice system, and instructions for using it, for preparing and removingtransparent biological tissue in a very gentle and accurate manner,especially in the eye, and more particularly in the human eye lens,during refractive laser surgery or cataract surgery, especially to treatpresbyopia by restoring the accommodative ability of the lens body.

A navigation apparatus includes a plurality of components and makes itpossible, on the one hand, to explore and analyze the structure withinan optical element and, on the other hand, to process and/or modify thisoptical element at the then defined locations. Such a navigationapparatus allows structures within the optical element, and theprocessing of the optical element with point accuracy as a function ofthe detected structures. Particularly preferably, the apparatus can beused for ophthalmological purposes.

An optical element is an element allowing an optical path to passtherethrough. Preferably, the element has a different refractive indexthan that of the surrounding medium. Particularly preferably, therefractive index of the optical element is greater than that of thesurrounding medium. The optical element is the area or object which isexamined and/or processed using the navigation apparatus. The opticalelement preferably has inner structures. For example, the opticalelement may have a multilayer construction, including layers ofdifferent refractive index. It is also conceivable for the opticalelement to have a single-layer construction. Furthermore, the opticalelement may have an internal pattern of materials having differentrefractive indices. The optical element may have an optically activeshape, such as a lens shape.

The optical analysis is an examination of the optical element using anoptical apparatus, preferably an ophthalmological apparatus, which canbe used to detect inner structures of the optical element and/or theindividual position of the optical element and/or of the respectivestructures. The inner structures of an optical element may be, forexample, interfaces or layers of various elements that make up theoptical element. A vitreous body, for example, may be comprised of acore that is surrounded by various additional layers in an onion-likemanner. Due to the growth process, the human eye is also composed ofvarious layers, which form an inner structure allowing them to bedistinguished from each other. An eye includes an embryonic nucleus,which is surrounded by a fetal nucleus, which in turn is surrounded byan adult nucleus, which in turn is surrounded by a cortex. Therespective interfaces between the various nuclei can then be detected asinner structures during optical analysis.

The navigation apparatus is also designed to modify and/or process theoptical element, thereby making it possible to change its opticalproperties.

Thus, it is possible, for example, to alter structures within theoptical element, to make incisions, to partially destroy the opticalelements and dissolve portions thereof, to change the refractive indexof the material of the optical element in specific areas, to formspecific cutting geometries in the optical element, and to therebychange the shape and/or flexibility of the optical element, particularlyto increase it.

Especially preferably, a provision is made for a detection device toperform the optical analysis of the inner structure of the opticalelement. This optical detection device is designed to detect, andpreferably visualize, inner structures within an optical element. Inthis connection, the determination of optically refractive propertiescan be performed using, for example, aberrometers or refractometers,preferably dynamic aberrometers, and expressed in the form of therespective Zernike polynomials. Particularly preferably, it is possibleto use dynamic wavefront diagnosis or a system for dynamic stimulationof the aberrometry. The geometric data of an optical element can also beacquired by devices which operate based on optical coherence tomography(OCT), or which include rotating slit Scheimpflug cameras, confocallaser scanners, and ultrasonographs.

In addition to the optical analysis of the inner structure, it isparticularly preferred to perform an optical analysis to determine thecurrent age-related condition of the optical element or lens. Thus, in asubsequent step, a therapeutic pattern which is adapted to theindividual lens can be applied using, for example, scanned fs laserradiation. This has the advantage over standard forms of treatment thatthe greatest possible range of accommodation can be provided in anoptical element, for example, an aged human eye, with a minimum amountof cut area and therapeutic effort, which avoids excessive therapeuticmeasures. To this end, for example, dynamic wavefront diagnosis isperformed using a dynamic aberrometer or refractometer to determine thedynamic optical properties of the individual eye expressed in the formof the respective Zernike polynomials. In the simplest case, wavefrontsare preferably measured for positive accommodation and for negativeaccommodation and used to determine the associated range ofaccommodation. Other properties which may be determined include thespeed at which the range of accommodation is traversed and/or thewavefront data generated during this process. It is particularlypreferred to also determine visual defects of the patients, thetopography of the cornea, the respective pupil size, and theillumination parameters of the stimulation target. In this manner,information is obtained about the range of accommodation and thereaction times of the eye. This allows a comprehensive, objectiveassessment of the dynamic refractive properties of the eye, which can beused, for example, to characterize the degree of presbyopia. Thisinformation, too, can be used subsequently, for example, in a controllerto calculate an individual cutting pattern and applied by a processingdevice. In this manner, the accommodation process can also be taken intoaccount in the finite element simulation. The radial offset at theciliary body of the individual eyes and/or lens images in theaccommodated and disaccommodated conditions can then be used toindividually determine cuts which will improve the accommodative abilityof this particular lens. If the fs-laser cuts are then also integratedin this modeling, the resulting deformations will correlate with thereduced tissue stiffness. In this manner, the range of accommodation canbe restored to the greatest extent possible in the individualoptomechanical eye model with as few cuts as possible, in particularoutside the natural aperture of the pupil during daytime.

Particularly preferably, the aperture, in particular the numericalaperture, of the detection device is smaller than 0.25. Using such anaperture, it is possible to examine and process the lens within an agedhuman eye.

With such an aperture, a laser focus having a diameter of about 5 μm canbe produced within the scanned lens of the human eye while the pupil iswide open, so as to navigate through and treat the lens in a scanningmanner. When using a confocal system, the diameter of the confocalaperture in the detector unit can be selected accordingly.

The processing device is a component that allows the optical element tobe modified and/or processed. This is preferably done in the interior ofthe optical element, especially preferably using radiation. Theprocessing device can then be used to change the structure within theoptical element. This device allows cuts bubbles, bubble fields,subdisruptive or disruptive regions to be created within the opticalelement. Particularly preferably, a laser is used as the processingdevice depending on the material to be processed, the laser beingconfigured to enter the optical element via the optical path, and toproduce its effect at a predetermined location therein. In the case ofthe human eye, it is especially preferred to use a laser systemgenerating pulses having a duration in the femtosecond range (<1 ps) anda wavelength in the visible or NIR range. In this manner, an effect canbe achieved within the eye by focusing at the desired depth and becauselarge portions of the eye do not absorb the radiation. It isparticularly preferred for the processing device to also includescanners for three-dimensional deflection and alignment of a focusedbeam.

Preferably, the processing device is moved along, or in a fixedrelationship to, the analyzed inner structure of the optical element.Thus, the processing device can be used to produce an effect along theinner structure, for example along the onion-skin-like interface betweenthe individual layers. In this context, “along the structure” means thatthe effect produced by the processing device in the optical element isspatially oriented relative to the detected inner structures and layers.Thus, the processing device could, for example, produce an effect, suchas a cutting pattern, parallel to and at a predetermined distance fromthe detected interface. It is also possible to select a fixedrelationship between the analyzed inner structure and the region ofaction of the processing device. The detected interface, according tothe optical axis of the optical element based on a function to bedefined, provides a cutting geometry whose distance from the detectedinterface or inner structure may differ, for example, between the centerof the optical element and the peripheral area. Similarly, it ispossible for the cutting plane to extend in a sinusoidal pattern alongthe detected interface at a distance therefrom. This allows arelationship to be created between the effect of the modification orprocessing operations performed by the processing device on the onehand, and the detected inner structures on the other, said relationshiptaking into account the detected conditions.

Also particularly preferably, a controller is provided by which acalculation of the basic data for the processing device is derived fromthe data or information that is obtained by the detection device. Such acalculation can be based, for example, on the finite element method, andis thus used to determine suitable data representing coordinates on thebasis of which the processing device will then perform modifications orprocessing operations within the optical element. It is then possible,for example, to predetermine an optimized cutting pattern by which, in ahuman eye, a pattern is defined between, or in relation to, theindividual interfaces which pattern will increase the accommodativeability of the eye or optical element by increasing the flexibility ofthe optical element in the area of the detected inner structures. Thismakes it possible to improve the accommodative ability of an aged,presbyopic human eye.

In a preferred exemplary embodiment of the present invention, detectiondevice (10) includes a confocal detector and/or a detector based onoptical coherence tomography.

Particularly preferably, a confocal detector is used for determining thegeometrical data of the optical element. A confocal detector operatesaccording to the principle of confocal detection, which is known fromthe microscopy of partially transparent tissue. In accordance with thisprinciple, a focal point of a laser is scanned across the tissue and thelight scattered back from this focal point is detected by a detectorwith an aperture disposed in a plane optically conjugate to the focalpoint. In this manner, light scattered back is differentiated from lightfrom the surroundings, and a high imaging factor is achieved. In anormal light microscope, the image is a superposition of a sharp imageof the points in the focal plane and an unsharp image of the pointsoutside the focal plane, whereas in a confocal microscope, theexcitation light is focused into the sample. Light from this focus isimaged through the same objective lens onto a pinhole, from which it isdirected onto a detector (usually a photomultiplier or an APD).

Therefore, the excitation focus and the detection focus are confocal toeach other, i.e., coincide.

It is also preferred to use a detector based on optical coherencetomography. This method is abbreviated as OCT and is an investigativetechnique in which short-coherent light is used with the help of aninterferometer for measuring the distance of reflective materials. Theequivalent acoustic method is ultrasound diagnostics (sonography). Thus,a three-dimensional image of the optical element can be reconstructedfrom reflections at interfaces of materials having different indices ofrefraction. This reconstruction is referred to as tomography. In therelated art, this examination is used, for example, to examine thefundus or rear portion of the eye, because competing technologies, suchas the confocal microscope, produce inadequate images due to a retinalayer structure of about 250 to 200 μm retina and because of the smallpupil size and the large distance between the cornea and the retina. Inan embodiment of the present invention, unlike the practice heretofore,this method is usable in conjunction with the proposed navigation deviceto examine and process the eye lens.

In a preferred exemplary embodiment of the present invention, theaperture of the detection device is smaller than 0.25 and larger than0.1, in particular smaller than 0.22 and larger than 0.18.

Using a detection device having an aperture of such a size, it isparticularly preferably possible to examine the lens of an aged humaneye. Especially preferably, the aperture is about 0.2.

In a preferred exemplary embodiment of the present invention, thedetection device includes a polarization optical sensor system.

When using polarized light, a polarization optical sensor system makesit possible to examine the distribution of mechanical stresses intransparent bodies. When using monochromatic light, a system of dark andlight stripes is produced whose arrangement allows reliable conclusionsto be drawn about the distribution and magnitude of the mechanicalstresses at all points of the optical body. Thus, the detection deviceallows the inner structures to be additionally examined with respect tothe stress distribution in the optical element.

In a preferred exemplary embodiment of the present invention, theprocessing device includes a laser, in particular an fs laser,especially a laser producing a scanned, focused, ultra-short pulsedlaser beam.

The lasers which are preferably used are scanned, focused, fs laserbeams with a pulse width of less than 1 ps, particularly preferably ofabout 300 fs, with a pulse energy of 0.1 to 10 μJ, preferably 1 μJ, anda focus diameter of about 5 μm. The wavelength of the laser system ispreferably between 400 and 1300 nm, particularly preferably between 780and 1060 nm. The fs laser is a laser emitting high-intensity lightpulses with durations in the femtosecond range. In fs lasers, energy iscompressed into an extremely short time interval by mode locking.Therefore, fs lasers have significantly higher peak powers thancontinuous lasers. The advantages of using fs lasers include, inparticular, high peak intensities, low heat transfer to the substrate,and the large spectral bandwidth. In metrology, the fs laser can also beused in the field of optical coherence tomography. Therefore, an fslaser can particularly preferably be used by the detection device toperform optical coherence tomography, and the same fs laser can be usedas an element of the processing device to perform modifications andprocessing operations in the optical element. In that case, thedetection device and the processing device largely coincide in terms ofconstruction, because they use the same fs laser.

In a preferred exemplary embodiment of the present invention, theprocessing device is designed to produce radiation in the opticalelement in order to stimulate subdisruptively with pulse energies belowor equal to 1 microJ and/or to perforate disruptively with pulseenergies above 0.1 microJ and/or to cut by creating rows of narrowlyspaced, disruptively produced bubbles. Thus, the processing device canbe used to modify and/or process the optical element in various ways.Thus, all gradations are possible, ranging from light stimulation to theapplication of continuous cuts.

Due to the focused beams, ultra-short pulsed laser radiation produces asubdisruptive or disruptive modification in the target region of thebeam in the optical element. A disruption is a mechanical deformationwhich is achieved mechanically by vaporizing material in the targetregion and by the resulting expansion. In the case of subdisruptivestimulation of the target region, the pulse energies used are of lowintensity, so that the aforementioned mechanical effect, which is alsofound, for example, in ultrasound, will not occur.

Selecting pulses of higher energies will result in disruptive mechanicalmodification of the target region by corresponding formation of bubbleswithin the tissue. The individual bubbles preferably have spot diametersin the range of a few μm. Thus, it is possible to perforate the targetregion; i.e., to create permanent holes therein. In the case of the eye,these holes are then quickly filled with liquid or neighboring, moreliquid tissue. Ultimately, this pattern and modification applied to theoptical element increases the deformability of the optical element,because the removal of the corresponding material at the bombarded sitesmakes the overall optical element more flexible, allowing it to deformmore easily. Particularly preferably, it is also possible to create rowsof individual, disruptively produced bubbles having spot diameters andspot distances in the range of a few μm, and to completely superimposesaid bubbles in this manner such that a continuous cut will be produced.These cutting geometries and patterns can then be applied to the eye oroptical element, it being particularly preferred for said cuttinggeometries and patterns to extend along the detected, inner geometricstructure of the optical element. With these bubble fields, anultra-short pulsed laser system is capable of creating patterns whichproduce, for example, cuts extending along one of the detectedinterfaces at a perpendicular distance of 0.2 mm therefrom,respectively. It is also conceivable to produce cuts relative to thisdetected interface within the optical element at distances between 0.1to 1 mm using sinusoidal modulation. Furthermore, these patterns areunderstood to be any geometric cutting patterns or bubble fields which,within the lens of the optical element, are brought into a fixedgeometric relationship with an anatomical structure which has previouslybeen detected by the measurement system.

In a preferred exemplary embodiment of the present invention, opticalelement (50) includes a lens, in particular an aged eye lens.

The aged eye lens frequently has hardenings which result in a loss ofthe accommodative ability of the eye.

Due to the phases of growth, the eye has various nuclei which differ inage and are superimposed on each other in an onion-like manner. Theinnermost and thus oldest nucleus hardens as it ages. By usingembodiments of the present invention, it is now possible to provide anapparatus which detects the respective interface structures between thevarious nucleus layers and components in order to subsequently improvethe flexibility of the hardened older, inner nucleus by applyingsuitable cutting or bubble patterns. It is also conceivable that one ormore of these inner hardened nuclei could be completely removed andreplaced with gel.

In a preferred exemplary embodiment of the present invention, navigationapparatus (1) includes an ophthalmologic suction/irrigation device (30)having at least one cannula (35).

Such a device is particularly preferably used to fragment and remove ahardened inner nucleus of the human eye lens and to replace it with asuitable gel. This makes it possible to replace only the innermostnucleus of the lens while the outermost layers of the nucleus of thelens are retained as a supporting structure which ensures, inter alia,that the gel introduced will remain at the location formerly occupied bythe inner nucleus. Thus, the flexibility of the eye lens, and thus itsaccommodative ability, can be significantly improved.

This is particularly preferably done using an ophthalmologicsuction/irrigation device, such as is used in phacoemulsification. Sucha suction/irrigation device typically includes one or two cannulasthrough which the fragmented nucleus can be removed. Thus, an fs lasercan be used to reduce the inner nucleus of an eye lens to smallfragments having a diameter of less than 1 mm, which can be suctionedoff through a suction/irrigation device. This prepared lens nucleus iscompletely removed using a suction/irrigation device such as is used,for example, in the conventional phacoemulsification technique, or byway of a device using a different suction/irrigation principle. Theresulting hollow lens body can now preferably be filled with anartificial or natural, biocompatible, flexible, transparent gel materialthrough a cannula, or preferably bimanually; i.e., using two cannulasinserted at opposite sides, so as to restore the optical function andaccommodative ability of the lens.

Particularly preferably, the cannula has a tip which is configured suchthat when it is inserted, in particular into the lens cortex, it willurge the material sideways and not forward, so that a self-sealingeffect will be produced after the gel filling process is complete. Thisshort-pulsed laser assisted, partial phacoemulsification prevents thedevelopment of a secondary cataract and, in addition, avoids ashortcoming of the currently clinically studied gel fillings of thewhich are introduced into the capsular bag after a preceding completephacoemulsification. The problem here is that the entire nucleus of thelens must be removed, as a result of which the gel cannot be adequatelyfixed in place. In addition, remaining proliferating cells of theremoved lens may produce an opacity of the posterior membrane of thecapsular bag. This secondary cataract (posterior opacity) isconventionally treated by photodisruption using a Q-switched Nd:YAGlaser, whereby the opacified posterior membrane of the capsular bag isremoved from the optical path of the eye. However, if the capsular bagis completely filled with gel, this method cannot be used because thegel would flow out. By the partial gel filling within the cortex of thenatural lens in accordance with an embodiment of the present invention,on the one hand, the secondary cataract rate is significantly reducedand, on the other hand, the gel is additionally encapsulated and, inparticular, the hard nucleus is replaced by a flexible gel so as torestore the accommodative ability.

In another preferred embodiment, after the lens body produced by thepartial phacoemulsification has been filled, the filling materialintroduced is exposed to electromagnetic radiation, for example UVradiation, which produces a change in the consistency and/or viscosityof the gel. In this manner, the gel is prevented from leaking orescaping from the lens body at a later time.

In another advantageous embodiment, the treatment with electromagneticradiation, for example UV radiation, may be used to subsequentlyfine-tune the refractive power of the new gel-like lens nucleus by wayof objective and/or subject assessment by the patient.

The inventive apparatus for navigated intraocular, ultra-short pulsedlaser cutting can also be used for ultra-short pulsed laserfragmentation of the entire lens in the conventional phacoemulsificationof the entire lens. There is then no need to conventionally liquefy thelens using ultrasonic vibrations. Instead, the lens fragments producedby the above-described laser cuts can simply be suctioned off using thesuction/irrigation device. This novel method reduces the duration of theinvasive surgery and the thermal load on the eye.

Furthermore, the inventive apparatus for navigated intraocular,ultra-short pulsed laser cutting can be used for cutting of theposterior membrane of the capsular bag in order to treat secondarycataracts. Unlike the conventional ns Nd:YAG-Laser, the fs laserprovides for a gentler treatment because of the lower disruptiveenergies, which are reduced from several mJ to a few μJ. When usingconventional Nd:YAG disruptive lasers, the focus is located behind themembrane of the capsular bag in order to destroy the membrane by way ofthe acoustic shock wave and to safeguard the artificial lens, whereaswhen using the high repetition fs laser and the coupled navigation, thefocus will be located on or in the immediate vicinity of the membrane.

An embodiment of the present invention provides an apparatus forplanning the therapy of a human eye, the apparatus comprising a dynamicwavefront measurement device (aberrometer) for acquiring wavefront data,and a diagnostic device for determining geometric parameters of theoptical apparatus of the eye (an anterior chamber OCT and/or a rotatingScheimpflug camera and/or an ultrasonic 3D measurement system and/or eyelength measurement devices and/or a topography measurement device), andfurther comprising a controller for consistent superposition of theacquired wavefront data and geometric data, and an additional controllerfor planning the most efficient therapeutic laser cutting paths.

The dynamic wavefront measurement device used may be an aberrometer.Such a device is used to acquire wavefront data of the entire eye.

The diagnostic device used for determining geometric parameters of theoptical apparatus of the eye may be an anterior chamber OCT and/or arotating Scheimpflug camera and/or an ultrasonic 3D measurement systemand/or eye length measurement devices and/or a topography measurementdevice. Such a device is used, in particular, to acquire data of thelens.

A first software package is used in conjunction with the controller toachieve a consistent superposition of the acquired wavefront data andgeometric data. This produces an overall image of the lens and of theoverall optical apparatus of the eye.

A second software package is used in conjunction with an additionalcontroller to plan the most efficient therapeutic laser cutting paths.This is preferably done using the same controller as in the previousstep. In this connection, it is possible to take into account not onlythe geometry of the lens, but also any visual defects of the overallapparatus, thus making it possible to determine a cutting path whichtakes into account the individual conditions of this eye and which willimprove the accommodative ability thereof. This determination can bedone using, for example, the finite element method.

An embodiment of the present invention provides a method for modifyingan optical element, in particular a human eye lens, using a preferablyscanned, focused and pulsed laser beam, the modification being performedin accordance with the following steps: completely measuring the dynamicoptical wavefront of the eye during accommodation and the associatedgeometric parameters to individually plan an fs-laser cutting therapy;detecting the position, geometry and inner structure of the eye lens;selecting a basic cutting pattern composed of a plurality of planes;developing a protocol defining the cutting paths by adapting orconverting the basic pattern to match the detected individual geometryof the eye lens; indifferentiating the positioning system with respectto the position of the eye lens; and making the surgical cuts using thelaser system according to the established protocol.

FIG. 1 shows, in a schematic view, a navigation apparatus 1 according toan embodiment of the present invention. Navigation apparatus 1 includesa detection device 10, which is equipped with an optical confocal and/oroptical coherence tomography device and with a polarization opticalsensor system 15. Also provided is a processing device 20. Detectiondevice 10 and processing device 20 are connected to a controller 40. Asuitable optical path may extend from detection device 10 and processingdevice 20 via scanning minors into an optical element 50, here amultilayered lens. In lens 50, various inner structures of the opticalelement are denoted by reference numeral 55.

The inner structure 55 of lens 50 is detected by detection device 10.This process is assisted by a sensor system 15, which makes it possibleto obtain a three-dimensional image of this inner structure 55 that iseven more comprehensive and is also dependent on the stress ratio.Preferably, detection device 10 also includes a device for dynamicwavefront diagnosis to measure the range of accommodation of the opticalelement or eye lens during positive accommodation and negativeaccommodation, and to measure the speed at which the range ofaccommodation is traversed. Preferably, detection device 10 also detectsvisual defects, the topography of the cornea and the respective pupilsize, as well as illumination parameters of the stimulation target. Itis particularly preferred to selectively dynamically analyze the sphere,the cylinder, or any higher-order aberrations. In addition, detectiondevice 10 can also acquire geometric data of the eye, using, forexample, devices based on optical coherence tomography or rotating slitScheimpflug cameras, confocal laser scanners, and by ultrasonographs.This information is transferred to controller 40 which calculates targetcoordinates for processing device 20 using a finite element model.Particularly preferably, the data is first transferred to the controllerin order for it to calculate preferred cutting geometries which, whenapplied to the eye, will, for example, increase the accommodativeability. Thus, a pattern that is likely to provide the highest increasein the amplitude of accommodation can be determined using, for example,the finite element method. Thus, when the simulation is completed, shotparameters are provided which will then by used by the laser to applythese cutting geometries to the optical element and/or eye lens. Thecontroller passes this data on to processing device 20, from where thelens 50 will be processed in the predetermined manner. The shot patternand the cutting geometries being applied are oriented relative to innerstructure 55 of lens 50. This makes it possible to make therapeutic cutswhich extend along the detected planes, or along geometric structuresassociated with these planes, and which are produced, for example, byway of bubble fields produced by a processing device 20 in the form ofan ultra-short pulsed laser system. Thus, an embodiment of the presentinvention provides the advantage of a diagnostically and therapeuticallycoupled system for carrying out suitable and minimally invasivetherapies in a manner that is adapted in the best possible way to theindividual anatomy of a human eye lens. Natural slip planes areregenerated by way of the anatomically coupled cutting paths, whichensures high physiological compatibility of the therapy.

FIG. 2 shows, in a schematic view, the construction of the human eye.Also shown are cutting patterns, which have been applied using theinventive apparatus shown in FIG. 1.

As an optical element 50, the structure of a human eye is designated byreference numeral 50. The eye has an individual geometry andanatomically existing discontinuity planes, such as interfaces betweenthe various components of the nucleus. The figure shows embryonicnucleus 55 a, fetal nucleus 55 b, adult nucleus 55 c, and cortex 55 d.The anterior capsule is denoted 55 e. Thus, eye 50 contains naturalinterfaces or boundaries, for example, between embryonic nucleus 55 aand fetal nucleus 55 b and between fetal nucleus 55 b and adult nucleus55 c, etc. These interfaces are represented in the figure by continuouslines. Also plotted are dotted or dashed lines representing cuttingpatterns 25. Thus, for example, a cutting pattern 25′ extends on theside of fetal nucleus 55 b along the interface between fetal nucleus 55b and adult nucleus 55 c. This cutting pattern 25′ extends in asinusoidal pattern along the interface or inner structure 55 of lens 50.Also shown are cutting patterns 25 a and 25 a′, which have been creatednear the interface between adult nucleus 55 c and fetal nucleus 55 b onthe side of the adult nucleus in approximately parallel relationshipwith said interface and at a predetermined distance therefrom.

By the application of the cutting patterns 25, which extend along thedetected planes, or along geometric structures associated with theseplanes, and which are produced by way of bubble fields produced by anultra-short pulsed laser system, these act as anatomically coupledcutting paths and increase the flexibility of the interface betweenfetal nucleus 55 b and adult nucleus 55 c. In this manner, the eye canaccommodate better and partially loses the limitations caused byage-related hardening of the lens nucleus. Particularly preferably, thecutting path used for applying cutting pattern 25 starts at the pointwithin the eye that has the greatest distance from the apex of thecornea in order to ensure the best possible focus quality of the laserspot and to successively produce scattering centers for the parasiticlaser radiation of the following laser spots. In this manner, theretinal laser load can be minimized.

FIG. 3 shows, in a schematic view, two cutting patterns in the opticalelement. The figure consists of two subfigures, namely FIG. 3a and FIG.3 b, showing different cutting patterns, respectively.

FIG. 3a is a very schematic, simplified view of a lens 50 having aninner structure 55 in the form of a hardened inner nucleus. The dashedlines represent a first possible cutting pattern geometry 25, which isintended to increase the flexibility and, thus, the accommodativeability of lens 50. The cuts forming cutting pattern 25 extend radiallyoutward from the center of the lens nucleus and end at geometricdiscontinuity planes 55 of the lens. Due to the cylindrical geometry ofthe lens, the cuts shown in a cross-sectional view are made on conesegments. In FIG. 3 a, the cuts extend only in the nucleus of the lens,because this is where the rigidity of the lens is greatest and,consequently, where a maximum effect can be achieved to restore theaccommodative ability.

FIG. 3b shows a pattern 25, which is particularly beneficial forpatients who are expected to develop a cataract in the nucleus. Theradial cuts are only made in the cortex. In addition to the radial cuts,a further cut is made along the discontinuity plane between the nucleusand the cortex. The cutting pattern is preferably produced in a knownmanner using a scanned, focused, fs laser beam with a pulse width ofless than 1 ps (preferably 300 fs), with a pulse energy of 0.1 to 10 μJ,preferably 1 μJ, and a focus diameter of about 5 μm. The wavelength ofthe laser system is preferably in the range between 400 and 1300 nm,particularly preferably between 780 and 1060 nm.

Preferably, the anatomically coupled cutting paths do not extend acrossthe entire lens diameter, but only in a peripheral area, an optical zoneof the eye having a diameter of, for example, 3 mm, preferably 2 to 7mm, being left untreated, or being treated only in a central pupil areahaving a diameter of, for example, 7 mm. In that case, a peripheral arearemains untreated. When the treatment is performed in the peripheralarea, it is preferred to use mirror contact glasses, whereas when thecentral area is treated, simple contact glasses are used.

FIG. 4 shows, in a schematic view, a further embodiment of the presentinvention, which is used in partial phacoemulsification. Similarly toFIG. 2, FIG. 4 shows a schematic cross-section through the human eye,illustrating the various nuclei and corresponding interfaces. FIG. 4shows that embryonic nucleus 55 a and fetal nucleus 55 b (herecrisscross hatched) were emulsified; i.e., the nuclei were reduced tofragments having a diameter of less than 1 millimeter. Also shown is acannula 35, which is laterally inserted into lens 50 and through whichthe fragmented material can then be removed. After that, a suitable gelfilling can then be introduced therethrough. It should be noted that itis particularly preferred to use two cannulas 35, the second cannulabeing inserted into the lens from the other side, which is not depictedbecause only half of the lens is shown here. In this way, it is possibleto suction material off through one cannula while introducing irrigationfluid through the other cannula so as to assist or improve the removalprocess. Subsequently, the gel can be introduced in the same manner, andthe remaining irrigation fluid, which is displaced by the gel, can beremoved through the aspiration cannula. Ideally, material iscontinuously supplied through one cannula while the other cannula isused to continuously suction off material therethrough.

In this manner, the inner hard nucleus of the aged human eye lens is cutout by the scanned, short-pulsed laser spots, and is at the same timereduced to small fragments with a diameter of less than 1 mm, which canbe suctioned off by a suction/irrigation device. In this case, the innerhard nucleus includes the two segments embryonic nucleus 55 a and fetalnucleus 55 b, but it could also include only one nucleus.

This prepared nucleus of the lens is then completely removed using asuction/irrigation device such as is used in the conventionalphacoemulsification technique, or by way of a device using a differentsuction/irrigation principle. In accordance with an embodiment of thepresent invention, the resulting hollow lens body is now filled with anartificial or natural, biocompatible, flexible, transparent gel materialthrough a cannula, or preferably bimanually; i.e., using two cannulasinserted at opposite sides, so as to restore the optical function andaccommodative ability of the lens. These cannulas, which have a diameterof about 1 mm, are preferably used to penetrate the eye, including thecapsular bag and the lens cortex. The punctures are preferably madeangularly during the preparation, so as to make it possible to takeadvantage of the self-sealing effect after the treatment. In addition,it is particularly preferred to select the consistency of the geldepending on the diameter of the punctures in such a way that theopenings will close. Particularly preferably, the tips of the cannulasare designed such that when they are inserted, in particular into thelens cortex, they will urge the material sideways and not forward, sothat a self-sealing effect will be produced.

This preferably short-pulsed laser assisted, partial phacoemulsificationprevents the development of a secondary cataract and, in addition,avoids a shortcoming of the currently clinically studied gel fillings ofthe which are introduced into the capsular bag after a precedingcomplete phacoemulsification. This shortcoming is that the secondarycataract, which occurs in 50 percent of cases as a result of remainingproliferating cells of the removed lens, which produce an opacity on theposterior membrane of the capsular bag, is treated conventionally byphotodisruption using a Q-switched Nd:YAG laser. In this treatment, theopacified posterior membrane of the capsular bag is completely removedfrom the optical path of the eye. It is then no longer possible tocompletely fill the capsular bag with gel, because the gel would flowout. By the partial gel filling within the cortex of the natural lensaccording to an embodiment of the present invention, on the one hand,the secondary cataract rate is significantly reduced and, on the otherhand, the gel is additionally encapsulated.

In partial phacoemulsification, which is used to partially remove thelens in the form of an inner nucleus, cutting is performed along acomplete path along the inner nucleus. In addition, the nucleus to beremoved is reduced to fragments using efficient geometric cuttingpatterns. Particularly preferably, the procedure starts at the pointwithin the eye that has the greatest distance from the apex of thecornea in order to ensure the best possible focus quality of the laserspot and to successively produce scattering centers for the parasiticlaser radiation of the following laser spots, and to thereby reduce theretinal laser load.

Particularly preferably, after the filling of the lens body produced bythe partial phacoemulsification, the filling material introduced isexposed to electromagnetic radiation, for example UV radiation, whichproduces a change in the consistency and/or viscosity of the gel. Thismakes it possible, firstly, to prevent the gel from leaking or escapingfrom the lens body at a later time. Secondly, the refractive power ofthe new gel-like lens nucleus can subsequently be fine-tuned by way ofobjective and/or subject assessment by the patient. This makes itpossible to produce a refractive index gradient in the regenerated lens,which will be efficient for the dynamic refraction.

Thus, a human eye is initially examined to fully determine the wavefrontdynamics (does the eye still have an accommodation range of 4, 3, 2 or 1diopters). Moreover, it is preferred to determine the associated,individual geometric shape for the minimum respective positive andnegative accommodation (curvature of the anterior and posterior sides ofthe lens and distances of the optical planes). From this data, acomplete description of this individual optical/geometrical system isgenerated by a software, for example, based on the finite elementmethod. An additional software can be used to calculate therefrom theoptimized cuts to be made in the lens by way of the laser system.

Thus, an ophthalmo-surgical device system is provided, and instructionsfor using it, for preparing or removing transparent biological tissue ina gentle and accurate manner, especially in the eye, and moreparticularly in the human eye lens, during refractive laser surgery orcataract surgery, especially to treat presbyopia by restoring theaccommodative ability of the lens body.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive. Itwill be understood that changes and modifications may be made by thoseof ordinary skill within the scope of the following claims. Inparticular, the present invention covers further embodiments with anycombination of features from different embodiments described above andbelow.

The terms used in the claims should be construed to have the broadestreasonable interpretation consistent with the foregoing description. Forexample, the use of the article “a” or “the” in introducing an elementshould not be interpreted as being exclusive of a plurality of elements.Likewise, the recitation of “or” should be interpreted as beinginclusive, such that the recitation of “A or B” is not exclusive of “Aand B,” unless it is clear from the context or the foregoing descriptionthat only one of A and B is intended. Further, the recitation of “atleast one of A, B and C” should be interpreted as one or more of a groupof elements consisting of A, B and C, and should not be interpreted asrequiring at least one of each of the listed elements A, B and C,regardless of whether A, B and C are related as categories or otherwise.Moreover, the recitation of “A, B and/or C” or “at least one of A, B orC” should be interpreted as including any singular entity from thelisted elements, e.g., A, any subset from the listed elements, e.g., Aand B, or the entire list of elements A, B and C.

LIST OF REFERENCE NUMERALS

1 Navigation apparatus

10 detection device

15 polarization optical sensor system

20 processing device

25 cutting pattern

30 ophthalmologic suction/irrigation device

35 cannula

40 controller

50 optical element/lens

55 inner structure of the optical element/lens

What is claimed is:
 1. A method for detecting structures within anoptical element of an eye and processing the optical element as afunction of the detected structures, the method comprising: acquiring,by a detection device, geometric data of an eye; transferring, by thedetection device, the geometric data of the eye to a controller;calculating, by the controller, target coordinates for a processingdevice including a laser, the processing device being connected to thecontroller; and applying a beam produced by the laser to the eyeaccording to the target coordinates calculated by the controller so asto process the optical element.
 2. The method of claim 1, wherein theacquiring, by the detection device, geometric data of the eye isperformed by using at least one of an optical coherence tomographydevice, a rotating slit Scheimpflug camera, a confocal laser scanner, oran ultrasonograph.
 3. The method of claim 1, wherein the applying thebeam produced by the laser to the eye produces bubble fields in the eyeat the target coordinates.
 4. The method of claim 1, further comprisingmeasuring, by the detection device using dynamic wavefront diagnosis, atleast one of a range of accommodation of the optical element during atleast one of positive accommodation or negative accommodation and aspeed at which the range of accommodation is traversed.
 5. A method forperforming partial phacoemulsification, the method comprising: cutting acomplete path along an inner nucleus of a human eye lens; reducing, witha laser, the nucleus to fragments using geometric cutting patterns; andremoving the nucleus of the lens using an irrigation device to produce ahollow lens body.
 6. The method of claim 5, further comprising fillingthe hollow lens body with a gel material.
 7. The method of claim 6,further comprising exposing the gel material to electromagneticradiation to effect a change in at least one of the consistency or theviscosity of the gel.
 8. The method of claim 5, wherein the reducing,with a laser, the nucleus to fragments using geometric cutting patternsis started at a point within the eye that has a greatest distance froman apex of a cornea.
 9. The method of claim 6, wherein the filling thehollow lens body with a gel material is performed using two cannulas atopposite sides of the hollow lens body.
 10. A method for modifying anoptical element using a laser beam, the method comprising: measuring adynamic optical wavefront produced by the optical element duringaccommodation; measuring geometric parameters associated with thedynamic optical wavefront; planning a fs-laser cutting therapy basedupon the measured geometric parameters; detecting a position, ageometry, and a structure of the optical element; determining a basicpattern of the detected geometry of the optical element; selecting abasic cutting pattern composed of a plurality of planes; developing aprotocol defining a cutting path based on the basic pattern of thedetected geometry; and modifying the optical element using the laserbeam according to the protocol.
 11. The method as recited in claim 10,wherein the optical element is a human eye lens.
 12. The method asrecited in claim 10, wherein the modifying is performed by surgicalcuts.
 13. The method as recited in claim 10, further comprisingfragmenting and removing an inner nucleus of the optical element. 14.The method as recited in claim 13, further comprising filling the innernucleus with a gel.